Moving coil voltage regulator



E. D. T. MORRIS MOVING con.. VOLTAGE REGULATOR Aug. 1799 1937.

Filed Sept.

@i Wa (Vf- Patented Aug. 10, 1937 PATENT OFFICE MOYING COIL VOLTAGEREGULATOR Eric Douglas Tobias Norris, Hollinwood, England, assigner toFerrantl Electric Inc., New York,

Application September 2,7, 1935, Serial No. 42,539 In Great BritainOctober 31, 1934 IClalm.

This invention relates to voltage regulators of the type embodying apair of fixed coils mutually associated so as to possess considerableleakage reactance and a third coil short clrcuited on ltself and devoidof any movable iron core, which l latter coil is capable of being movedinto positions adjacent to either of the said first named coils or intopositions intermediate thereof.

Voltage regulators in accordance with this invention are applicable to alarge number of uses and are particularly valuable in association withsystems of voltage regulation such as are described in United StatesPatent No. 1,901,768.

.Referring to the accompanying diagrammatic drawing:-

Figure 1 is a sectional front elevation of an existing form of voltageregulator.

Figure 2 is a sectional plan thereof.

Figure 3 is a central vertical sectional view thereof perpendicular toFigure 1.

Figure 4 is a sectional plan view oi' one form of voltage regulatorembodying the present invention, and

Figures 5 and 6 are side and plan views respectively of the core andside yokes of a modled form of voltage regulator embodying the presentinvention.

In these regulators as usually constructed hitherto the fixed coils havebeen assembled respectively at the top and bottom of a magnetic corewhilst the moving coil slides up and down the core between the two fixedcoils if 0f sandwich arrangement or over them if of concentricarrangement. In either alternative the shortcircuited moving coil actsas a shut-gate to the magnetic iiux. A typical example of such aregulator is indicated in Figures 1 to 3 in which 2 and 3 represent theilxed coils and I the shortcircuited winding devoid of any movable ironcore movable axially between the coils 2, 3. The flux passing through,say, the fixed coil 2 is, therefore, compelled to return through thespace between the fixed and moving coils as indicated by dotted linespassing across the windows of the core from the centre leg to the sideyokes. In addition to passing straight from the centre leg to the sideyoke or yokes, a considerable portion of flux fringes and passes fromthe sides a, a of the centre leg d to the sides b, b of the side yoke oryokes c, c as is evident from Figure 2.

Since the magnetic core is laminated this fringing ilux will enter orleave both the side yoke or yokes and the centre leg at a direction atright angles to the plane of the laminations.

Under these conditions the energy loss in the (Cl. P11-119) core is verygreatly increased. Moreover, in the case of oil-immersed regulatorscontained in a steel tank some of the frlnging flux will enter the tankwall as indicated at o and cause additional energy loss in the tank.Further, some of 5 this ux will also pass from the faces e, e of the topyoke f to the faces g, 9 of the centre leg d as shown in Figure 3causing additional energy loss in a similar manner.

The main object of the present invention is to 10 'eliminate or reducethese losses.

The invention consists briefly in a voltage regulator of the typeindicated having a common core 4associated with a plurality of sideyokes, the

planes of the laminations in at least one of said 15 side yokes beinginclined preferably at a considerable angle, e. g. to planes containingthe laminations in the other or in another side yoke.

In carrying the invention into effect according to one convenientexample as illustrated in Fig- 20 ure 4, I provide a central core whosecross section is in the form of a cross lying within a circle with whichare associated two sets h, h and m, m of side yokes, the laminations inone set being at right angles to the laminations in the other. 25

The core is subdivided into three parts, one part d comprisinglaminations associated with and parallel to the laminations in one setof side yokes m, m whilst the laminations in the other two portions k, kare associated with and are 30 parallel to the laminations in the otherset of side yokes h, h. i

I'here are thus two sets of laminations at right angles, one set havingparts m, m forming side yokes and further parts d forming part of the 35common core and the other set having parts h, h forming further sideyokes and further common core portions k, k.

The stationary and moving coils are disposed to encircle the core d, k,k and the side legs asso- 40 ciated with the respective side yokes,together with the side yokes proper, are disposed external to the coils.

With this arrangement the common core 1amlnations k, k approach nearerto the associated 45 side yokes h., h. than do the common corelaminations d and likewise the common core laminations d approach nearerto the associated side yokes m, m than do the other common corelaminations k, k.

In order that the core may have an approximately circular cross section,the core laminations d, k, k may be suitably graded in width.

In carrying the invention into eilect according to a modiiiedarrangement as illustrated in 55 Figures 5 and 6, I provide a commoncore composed ol' two sections of laminations, one section comprisingcore laminations n associated with and parallel to two sets of side yokelaminations p, p whilst the other core section o comprises laminationsassociated with and parallel to one set of side yoke laminations q.

The set of laminations having the parts p, n, p are at right angles tothe set of laminations having the parts o, q but the two core parts o, ntogether have an approximately circular cross section so as snugly toaccommodate the stationary and moving coils of the regulator.

In this arrangement again the common core laminations o approach nearerto the side yoke laminations q than do the core laminations n, n and thebulk of the common core laminations n approach nearer to the side yokelaminations p, p than do the core laminations o.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:-

A voltage regulator comprising, a pair of xed coils mutually associatedso as to possess considerabie leakage reactance, a third coil shortcircuited on itself, movably mounted with respect to said pair of coils,a set of laminations parts of which comprise side yoke laminations andother parts of which comprise common core laminations, a further set oflaminations inclined to the rst mentioned set, parts of the laminationsof said further set comprising further side yoke laminations and otherparts of the laminations of said further set comprising further commoncore laminations, said common core formed by said laminations having across section wherein at least some of the laminations of any individualset project from the body of the common core to form salients the entireouter faces of which are positioned away from the body of the core inthe direction of the respective side yoke 1aminations.

ERIC DOUGLAS TOBIAS NORRIS.

